Mark Deen at Bloomberg reports the income of the wealthiest 10 percent of the population is nine times greater than that of the poorest 10 percent and that gap has grown about ten percent in the last 25 years.

The US holds one of the most disproportionate earnings gaps, with the wealthiest earners making 14 times what lowest paid workers bring home.

In a statement OECD Secretary-General Angel Gurria said, "The social contract is starting to unravel in many countries. "This study dispels the assumptions that the benefits of economic growth will automatically trickle down to the disadvantaged and that the greater inequality fosters greater social mobility."

"There is nothing inevitable about high and growing inequalities," Gurria continued. "Up-skilling the workforce is by far the most powerful instrument to counter rising inequality. The investment in people must begin in early childhood and be followed through into formal education and work."

The growing gap is largely the result of paid wages which make up 75 percent of the household incomes of working adults.